Rabble-arm and rake.



H. N. THOMSON & W. M. KELLY.

RABBLB ARM AND RAKE. APPLICATION FILED AUG.16, 1909.

940,488. Patented Nov. 16. 1909.

2 SHEETS-SHEET 1.

INVENTORS.

I Henry N- Thomson Mlllw ellglu/g/ m4 A TTORNEY.

H. N. THOMSON & W. M. KELLY.

RABBLE ARM AND RAKE.

APPLICATION FILED AUG. 16, 1909.

Patented N0). 16, 1909.

2 SHEETS-SHEET 2.

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o o o 7 m m K HENRY N. THOMSON AND WILLIAM KELLY, OF ANACONDA, MONTANA.

RABBLE-ARM AND RAKE.

Specification of Letters Patent.

Patented Nov. 16, 1909.

Application filed Au'gust 16, 1909. Serial No. 513,156.

To all whom it may concern:

Be it known that we, HENRY N. THoMsoN and WILLIAM M. KELLY, respectivelya subject of the King of Great Britain and a citizen of the UnitedStates, residing at Anaconda, in the county of Deerlodge and State ofMontana, have invented certain new and useful Improvements inRabble-Arms and Rakes, of which the following is a full, clear, andexact description, reference being had to the accompanying drawings,forming a part hereof.

Our invention has relation to improvements in rabble-arms and rakes forfurnaces; and it consists in the novel construction of parts more fullyset forth in the specification and pointed out in the claims.

In the drawings, Figure 1 shows the outline of a conventional form ofMcDougall ore roasting furnace, with a partly sectional and partlyelevational view of our improved rabble-arm and rake; Fig. 2 is anenlarged vertical cross-section of the rabblearm taken on the line 2-2of Fig. l, with roofscraping blade or rake in end elevation; Fig. 3 is atop plan of the rabble-arm; Fig. at is a longitudinal middle verticalsection on the line 4.4 of Fig. 8;-Fig. 5 is a top plan of thein-feeding rake; Fig. 6 is an end view thereof; Fig. 7 is a top plan ofthe out-feeding rake; Fig. 8 is an end view thereof; Fig. 9 is an endview of the rabblearm viewed from the inner flanged end of the arm; Fig.10 is a top plan view of the roofscraping blade or rake;.and Fig. 11 isan end view thereof.

The present improvement though specially applicable as a rabblemechanism for ore roasting furnaces of the McDougall type, may of coursebe utilized as a feature of any stirring or rabble apparatus where thenecessity arises for keeping such apparatus cool, or at a temperaturesufiiciently reduced to escape the destructive effects of too great aheat.

The objects of the invention are to provide a hollow rabble-armaffording special facilities for the circulation of the cooling medium(preferably water); to bring the cooling medium in proximity to therakes thereby cooling the latter; to provide means by which the rakesmay be readily attached to the arm, and as readily detached therefromwhere occasion for renewal or repair of a rake arises; to provide meansfor removing accretions from the roof of the hearth over which the armstravel; to provide an arm and rake which will possess rigidity,stiffness and strength, and thereby resist any material tendency to sagunder a high temperature; and to provide further and other features ofconstruction, the advantages of which will be best apparent from adetailed description of the invention, which is as follows Referring tothe drawings, F represents a roasting furnace of the McDougall type,shown mainly in dotted outline. The hearths of the furnace arerepresented by 7b, the material or charge dropping from one hearth tothe next hearth below as well understood in the art. Passing through theseveral hearths is the rotatable hollow rabble-shaft 1, from whichradiate the series of rabble arms 2, extending into the several hearthsand carrying rakes 3, by which the material is successively fed from onehearth to the hearth immediately beneath it. To accomplish the feedingin the manner indicated, the rakes'on the arms in one hearth are set atan angle opposite to that of those in an adjacent hearth, all as fullyunderstood in the art.

Into the hollow shaft is inserted a waterfeed pipe 4 (this being acommon and well known method of introducing the water) which dischargesinto the bottom of the shaft whence the water circulates through theseries of arms, and upward through the shaft. In the present improvementthe hollow rabble arm is provided with a top, inwardly and upwardlysloping wall, to facilitate the circulation from the outer end of thearm toward the shaft, though this particular feature is not new, nor isit claimed herein.

The improvements are directed to the following details of construction:-The crosssection of the arm is substantially as shown in Fig. 2, thearm being provided with a central basal dove-tailed stiffening rib 5 inwhich is longitudinally disposed the watercirculating basin or channel6, the bottom of the channel being sufliciently depressed below thesurfaces forming the bottom of the hollow chamber of the arm, on eitherside of the rib, to bring the cool inflowing water in close proximity tothe rakes suspended from the rib. On opposite sides of the rib 5, alonthe bottom of the arm are formed dove-talled grooves 7 which receive thecorrespondingly shaped tongues or projections 8, formed on the sides ofthe rake-supporting heads or plates 3?, the rib 5 being in turn receivedby the dove-tailed groove 9 formed by the tongues 8. This constructionleaves the outer sides of the tongues 8 protected against direct contactwith the fur nace charge and dust, such protection being accorded themby the lower side portions 10, 10, of the arm, by which said tongues arevirtually embraced. To effectively cool these portions 10, the sides ofthe bottom of the chamber of the hollow arm are formed into conductingchannels 11, 11, depressed somewhat below the plane of said bottom, suchdepression reducing the thickness of the metal in the corners of thechamber whereby a more effective cooling results from the watercirculating through the arms. The rakes or blades 3 are stiffened byribs 12, 12 connecting the opposite faces thereof to the rake-heads 3 asshown. Formed at the upper outer terminal of the rabblearm is aclove-tailed rib or tongue 13 over which is passed the base plate 14: ofthe roof-scraping blade or rake 15, the sides of the plate beingprovided with flanges 16 which embrace the sides of said tongue. Theblade 15 serves to remove any accretions which may accumulate on theroof of the hearth during the operation of the furnace. The plate 14:,arm 2, and the head 3 of the outer terminal rake 3 are provided withopenings 0 which when the rakes are properly positioned are brought intoregister and a common locking pin or key 17 is dropped through theopening or passage thus formed, which thus serves not only to hold theroof-scraper in place, but likewise locks the terminal rake 3 of theseries against displacement. The remaining rakes of course, are held inposition on the rabble arm by the terminal rake locked in the mannerindicated.

To remove a broken rake, the pin 1'7 is withdrawn allowing the rakes tobe slipped off their supporting rib 5, when the broken rake may beremoved and replaced by a new rake, the remaining rakes remounted, thelocking pin 17 reinserted, and the repair is done with a minimum loss oftime. The sides of the rake-head 3, between the rake 3 and the bases ofthe tongues 8 are beveled or inclined toward the rake as shown at a,this allowing free access of the charge to the rake as the arms sweeparound the axis of the rabble-shaft, the sides of the rake projectingsomewhat beyond the base of the in cline.

It will be seen from the drawings, that a substantially even thicknessof metal separates the rake-head 3 and its tongues 8 from the bottomsurface of the chamber of the rabble-arm traversed by the outwardlycirculating current of water, thereby bringing the water into close anduniform proximity to the entire top of the rake and keeping the lattercool. The central channel or basin 6 is depressed somewhat below thebottoms of the side channels 11 as shown to best advan tage in Fi 2. Thefacility afforded for the removal of the rakes obviously reduces theamount of breakage.

Having described our invention, what we claim is:

1. A hollow rabble-arm provided with a bottom stiffening rib traversedby an inner longitudinal channel for the flow of a circulating medium,the rib having disposcd on each side thereof longitudinal grooves.

9-. A hollow rabble-arm provided with a bot-tom dove-tailed stiffeningrib traversed by an inner longitudinal water conducting channel, the ribhaving disposed on each side thereof longitudinal dove-tailed grooves.

3. A hollow rabble-arm provided with a bottom dovetailed stiffening ribtraversed by an inner longitudinal water conducting channel, the ribhaving disposed on each side thereof longitudinal dove-tailed grooves,in combination with a rake having a head provided with tongues forinsertion in said grooves, and with a groove between the tongues forreceiving the rib of the rabblearm.

1. In combination with a hollow rabblearm provided with a bottomstiffening dovetailed rib traversed by an inner longitudinal waterconducting channel, the rib having disposed on each side thereoflongitudinal dove-tailed grooves, a series of rakes having headsengaging said rib and grooves, the bottoms of the sides of the armembracing the sides of the heads and protecting the same against thefurnace charge.

5. In combination with a furnace hearth, a rabble-arm, a series of rakesmounted thereon and detachable therefrom by a longitudinal movementthereof along the arm, an upper terminal roof scraping blade mounted onthe arm and movable longitudinally thereon, the blade, arm, and terminalrake of the series being provided with openings adapted to register withone another, and a common locking pin or key passed through suchregistering openings.

(5. A hollow rabble-arm having a chamber for the circulation of acooling medium, a bottom outer longitudinal rib bounded by grooves oneach side thereof, the chamber of the arm being provided with a centrallongi tudinal channel or basin traversing the rib, and with sidelongitudinal channels beyond the grooves, the several channels beingdepressed below the plane defining the bottom of the chamber aforesaid.

7 A hollow rabble-arm having a cham her for the circulation of a coolingmedium, a bottom outer longitudinal rib bounded by grooves on each sidethereof, the chamber of the arm being provided with a centrallongitudinal channel or basin traversing the rib, and with sidelongitudinal channels beyond the grooves, the several channels beingdepressed below the plane of the bottom of the chamber and the centralchannel being depressed relatively below the bottoms of the sidechannels.

8. In combination with a rabble-arm having a bottom longitudinal outerdove-tailed rib bounded by dove-tailed grooves, in combination with arake having a head-plate provided with tongues engaging said grooves,the sides of the plate being beveled from the bases of the outer sidesof the tongues toward the rake-blade, for the purpose set forth.

9. In combination with a hearth a rabblearm extending over the same, adove-tailed rib formed at the top of the outer end of the arm, and aroof scraper having a base-plate passed over and locked to said rib.

In testimony whereof we afliX our signatures, in presence of twowitnesses.

HENRY N. THOMSON. XVILLIAM M. KELLY. Vitnesses ULYSSES ANDERSON GARRED,STEWART M. h IoRRIs.

